What is the superheat, and what might it suggest?
Leak detection · EPA 608 Type II. The correct answer, and the reasoning behind it.
Signs of leaks in high-pressure systems and leak testing before charging.
The question
On an R-22 system, the evaporator saturation temperature is 40 °F and the suction line at the evaporator outlet measures 70 °F. What is the superheat, and what might it suggest?
- 30 °F; possibly low charge from a leakCorrect answer
- 30 °F; this points to an overcharged system
- 110 °F; a failed compressor
- 40 °F; a normal reading
Why “30 °F; possibly low charge from a leak” is correct
Superheat is the suction line temperature minus the saturation temperature: 70 - 40 = 30 °F. Superheat that high is well above normal for most systems, and excessive superheat is one of the signs EPA lists for a leak, because an undercharged evaporator runs out of liquid early.
Source: EPA: Test Topics
Why the other answers are wrong
- 30 °F; this points to an overcharged system — An overcharge tends to lower superheat, not raise it.
- 110 °F; a failed compressor — This adds the temperatures instead of subtracting them.
- 40 °F; a normal reading — 40 °F is the saturation temperature, not the superheat.
Practice more of this
More EPA 608 Type II practice questions, or see every EPA 608 practice test.
Unofficial, not affiliated with the EPA or any EPA-approved certifying organization. Questions are original practice written from public EPA material, not real exam questions.